Global Mapper v25.0

ECW with alpha channel. How to change transparent?

buyslake
buyslake Global Mapper User
edited October 2011 in Technical Support
Hello,

I created an ECW image with an alpha channel so I can turn the black area around the image transparent.
I do not see any option within Global Mapper to set the alpha channel transparent.

Please advise...

Comments

  • global_mapper
    global_mapper Administrator
    edited October 2011
    What version of Global Mapper are you using? When you load an ECW file with an alpha channel it should automatically be detected (or depending on how it is marked in the file you might be prompted to treat it as data or alpha) and used as an alpha. What are you using to create the ECW file?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • buyslake
    buyslake Global Mapper User
    edited October 2011
    What version of Global Mapper are you using? When you load an ECW file with an alpha channel it should automatically be detected (or depending on how it is marked in the file you might be prompted to treat it as data or alpha) and used as an alpha. What are you using to create the ECW file?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com

    Version 13

    The ECW was created with Erdas Imagine with the ECW transparency option.

    The ECW when viewed in ArcMap 10 first appears with the black border around the image. (the ecw image is an odd shape, Not square)
    In Arcmap, you can turn the alpha channel transparent. Then you only see the image. I was looking for this option in Global Mapper.
  • global_mapper
    global_mapper Administrator
    edited October 2011
    The alpha channel should automatically be treated as transparent. If you load the generated ECW into Global Mapper is the edge transparent? There is only an option to ignore an alpha channel since it will automatically be transparent.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com